Introduction aux Réseaux Locaux Industriels

Introduction to Industrial Local Area Networks (RLIs)

• Industrial Local Area Networks (RLIs) are communication systems connecting multiple industrial devices (sensors, actuators, controllers) within a limited geographical area.
• RLIs are defined by the components enabling high-speed data exchange between devices within a single company.

Needs of RLIs

• Increased market demand drives productivity growth.
• Reducing execution time of commands (automation).
• Reducing human error.
• Establishing interconnectivity between heterogeneous industrial equipment.
• Ensuring system integrity.

Types of Networks

• Wide Area Networks (WANs) cover distances greater than 100 km.
• Metropolitan Area Networks (MANs) cover distances greater than 1 km.
• Local Area Networks (LANs) cover distances less than 1 km.
  • The distinction is based on the distance between devices.

OSI Model vs. RLI Model

• The OSI model and the RLI model both describe network layers.
• The RLI model utilizes layers of cooperation (MMS) for industrial specific protocols such as LLC 1, 2, 3 and MAC, which are responsible for managing data communication across layers.

RLI Model Layers

• The application layer implements applications, controls, and builds necessary interfaces for communication.
• The link layer handles error correction and communication reliability using LLC protocols (LLC1, LLC2, LLC3).
• The physical layer encodes data for transmission and decodes received messages.

Industrial Environment: Equipment

• The industrial environment encompasses equipment involved in the production chain:
• Robots
• Machines
• Sensors
• Actuators
• Supervision stations

Industrial Environment: Objectives

• Rapidly market new products.
• Respond flexibly to market demands.
• Efficient and economical production.
• Optimize machine utilization.

Industrial Environment: Levels

• The industrial environment is organized hierarchically into four levels of abstraction.
• Business Level (Level 3): Management services (commerce, personnel, finance).
• Factory Level (Level 2): Production management (CFAO, GPAO, CAO, transport, quality control).
• Workshop/Cell Level (Level 1): Manufacturing, supervision, robots, and automatic systems.
• Field Level (Level 0): Basic manufacturing equipment (machinery, sensors, actuators).

Network Architecture

• An industrial local network connects various machines within a factory.
• The network enables control, monitoring, supervision, operation, maintenance, and product/process management.

RLI Traffic Characteristics

• Network traffic priorities differ from office networks.
• Industrial data prioritization depends on urgency and data size.

RLI Messages

• Industrial networks typically operate in real-time, which is critical to avoiding catastrophic failures.
• Urgent messages are immediate and vital.
• Non-urgent messages may be less critical such as reports or transfers.

Message Size

• The volume of traffic can differ based on the size and number of messages transferred, and the specific level involved.
• Short messages: Sensor data, simple commands
• Long messages: Programs, reports.

RLI Quality Requirements

• Reliability is essential as industrial equipment can generate interference.
• Operational stability is a critical characteristic that ensures continuous operation even when some components fail.
• Robust performance in fluctuating conditions to maintain continuity despite occasional issues.
• Specific communication characteristics must be considered to ensure proper network operation.

RLI Characteristics

• Simultaneous data transmission to multiple recipients (broadcast).
• Simultaneous requests for information intake (multi-access).
• Scheduled processes (cyclic measurements).